WRITINGS OF JAMES SMITIISON. 



23 



d. 9.2 grs. of these crystals, ignited in a covered tobacco- 

 pipe, lost 3.2 grs. = 0.3478 ; hence, these crystals consist of 



Carbonic acid 0.348 



Calx of zinc - - - 0.652 



1.000. 



Electrical Calamine. 



The Abbe HAUY has considered this kind as differing 

 from the other calamines only in the circumstance of being 

 in distinct crystals; but it has already appeared, in the 

 instance of the Derbyshire calamine, that all crystals of 

 calamine are not electric by heat, and hence, that it is not 

 merely to being in this state that this species owes the above 

 quality. And the following experiments, on some crystals 

 of electric calamine from Regbania in Hungary, can leave 

 no doubt of its being a combination of calx of zinc with 

 quartz ; .since the quantity of quartz obtained, and the per- 

 fect regularity and transparency of these crystals, make it 

 impossible to suppose it a foreign admixture in them. 



a. 23.45 grs. of these Regbania crystals, displaced 6.8 grs. 

 of distilled water, from a stopple-bottle, at the temperature 

 of 64 FAHRENHEIT ; their specific gravity is therefore = 

 3.434. 



The form of these crystals is represented in the annexed 

 Figure. 



cd=z 130. 



